Recycling

One of the advantages of thermoplastic composites is their inherent recyclability. We propose a feasible solution by using production and end-of-life reclaimed material. This waste is chopped into flakes with size order of centimeters and converted to new parts in a compression molding process. The challenge is to strike the right balance between structural properties and processing costs while maintaining a low variability of properties.

Background/Introduction

Thermoplastic composites are inherently easier to recycle than their thermoset counterparts, since both the fibre and matrix material can be recycled and fibre reclamation is not required. However, since their introduction into the market, research on recycling of TPC’s seemed to be still little, especially compared to thermoset composites. Within this project, the recycling loop of post-industrial thermoplastic composite waste will be studied, from shredding to re-processing.

Approach

As any other manufacturing process chain, production of thermoplastic composites generates waste. This waste is present in various types:

From prepreg material to consolidated cut-offs;

Almost virgin material or waste with impurities.

In any case, the value and performance of the fibre/matrix system still exists but the material might be shredded to smaller flakes so it can be processed further. The resulting component is then made of discontinuous fibres.

These discontinuous fibre composites have mechanical and processing performance largely influenced by the fibre length and flake aspect ratio. A certain fiber length is needed to achieve good mechanical properties. Hence, it is proposed to shred the material not smaller than to centimetre-sized flakes to prevent further down-cycling of the product.

After shredding, the flakes are re-processed. Long fibres are desired and thus manufacturing should limit fibre breakage. To do so, the reserach is focused on:

TPRC, the ThermoPlastic composites Research Center in the Netherlands, is an open innovation, research- and development center that aims for thermoplastic composites for a broad range of end use markets.